function second(second) {
    if (!second || second < 0) {
        second = 0;
    }
    return {
        day: Math.floor(second / (24 * 60 * 60)),
        hour: Math.floor(second / (60 * 60)) % 24,
        min: Math.floor(second / 60) % 60,
        second: second % 60
    };
}

function render(data) {
    var countdown = document.getElementById('jsCountdown');
    if (!countDown) {
        throw '#jsCountdown not exists.';
    }
    var daySpan = countDown.children[0],
        hourSpan = countDown.children[1],
        minSpan = countDown.children[2],
        secondSpan = countDown.children[3];
    var renderText = function (elem, val, append) {
        append || (append = '');
        var paddedVal = (val < 10 ? '0' + val : '' + val);
        elem.innerHTML = paddedVal + append;
    }
    if (!+data['day']) {
        daySpan.classList.add('hide');
    } else {
        renderText(daySpan, data['day'], '天');
    }
    renderText(hourSpan, data['hour'], ':');
    renderText(minSpan, data['min'], ':');
    renderText(secondSpan, data['second']);
}